When chemical compounds are in solid states, they can be either amorphous (that is, long-distance order does not exist in positions of atoms) or crystalline (that is, atoms are aligned with ordered repetitive patterns). Although in most cases, only a single crystalline form has been known for each of the compounds when they are in solid states, polymorphs have also been found in some compounds. The term “polymorph” refers to a specific crystalline form of a chemical compound that can take two or more crystalline forms (that is, a crystal lattice structure) in solid states.
On the other hand, the Compound A that is included in the present invention has already been known to be useful as a pest control chemical (see, for example, Patent Document 1). In the present invention, the pest control chemical refers to a chemical for exterminating harmful arthropods in the fields of agriculture and horticulture or of animal husbandry and hygiene (a chemical for exterminating endoparasites or ectoparasites, which are found in mammals or birds as domestic animals or pets; or a chemical for exterminating sanitary insects and unpleasant insects for household or business uses). In addition, a method for manufacturing the optically active substance of the Compound A has also been known already (see, for example, Patent Documents 1, 2, and 3).
Also, a crystalline polymorph related to the racemate of the Compound A (see, for example, Patent Document 4), and an amorphous material related to the optically active substance of the Compound A, which comes from an asymmetric carbon at position 5 of an isoxazoline ring have already been known (see, for example, Patent Document 1).